1. Field of the Invention
Exemplary aspects of the present invention generally relate to a sheet feed cassette and an image forming apparatus including the same, and more particularly to a sheet feed cassette capable of effectively transporting a sheet recording medium, and an image forming apparatus including the same.
2. Discussion of the Background
Image forming apparatuses such as a copier, a printer, a facsimile, a multi-functional printer and so forth are equipped with a sheet feed cassette (a sheet feed cassette as used herein includes a sheet feed tray and a cassette does not require removability from the image forming apparatus, although this may be possible). The sheet feed cassette is attachable and detachable relative to the image forming apparatus and stores paper. Paper, as used herein, includes a sheet, transfer member, printable media and the like. Typically, but not necessarily, paper is the medium of the sheet on which an image is to be formed. It should be understood, however, that the sheets, etc., are not limited only to paper.
In the image forming apparatus, i.e., a multi-functional copier, sheet feed rollers or the like separate the stored paper one sheet at a time and transport the sheets to an image forming portion. In the image forming portion, a toner image is transferred on the paper. The paper carrying the toner image is transported to a fixing unit so that the toner image is fixed. Ultimately, the paper is ejected to a catch tray. The sheet feed cassette includes side frames which regulate the alignment of the paper in a width direction perpendicular to a sheet conveyance direction. The cassette further includes an end frame which regulates the paper in a front-rear direction of the sheet conveyance direction, and a bottom plate urged in an upward direction by a biasing mechanism.
In such image forming apparatuses, a release coated paper which contains an adhesive material may be used. When such a paper is transported, the adhesive material may leak out of an end portion of the paper or a cut, and may stick to the sheet conveyance path and a storage surface of the sheet feed cassette. Along with the sheet transporting operation, the adhesive material continues to stick causing the sheet conveyance path to become contaminated with adhesive. Consequently, problems such as an interruption during transportation of the paper, paper jams and skew may occur.
When the adhesive material sticks to the side frames and/or the end frame of the sheet feed cassette which may be in close contact with the paper, the paper may be adhered to the side frames and/or the end frame generating the similar problems described above, because the end portion of the paper is pressed. Similar problems described above may be generated in a case where the adhesive material sticks to the bottom plate of the sheet feed cassette. In this case, since the laden weight of the paper is applied on the bottom plate, the paper may easily adhere to the bottom plate.